I finished Tomb Raider: Legend yesterday... well, at least the main storyline.  Overall I found it a quite enjoyable game.  Some of their visuals, particularly for outdoor water, are just fantastic and the gameplay is quite fun when it focuses on the acrobatics and traversal challenges rather than the simple combat or the sometimes obtuse puzzles.  The game uses a Dragon's Lair / Shenmue style mechanic during some of the cutscenes which I really enjoy.

There are, however, a few boss fights.  They are, for the most part, fine standard boss fights.  Two of them, however, definitely break some basic rules of what I would call "boss etiquette".  Be warned if you are particularly spoiler averse; while I will attempt to remain somewhat general I can't help but give some things away. 

These two problematic boss fights exemplify two different (yet sadly common) failure modes for boss fights.  They are nicely symmetric around the notion of how the user understands the basic mechanics of the fight.

In the first, we have a failure of explanation.  You fight a monster, which is clearly a monster, and you have tools for injuring the monster, yet the monster is actually impossible to kill and you have to do some other thing altogether while the monster annoyingly tries to stop you.  Introducing some totally separate objective with no clear explanation of this change, and requiring a finicky interface to do it no less, is just inexcusable.  If I have to frob the foozle in some specific way, then make that clear and make the challenge executing it, not even understanding that I have to do it in the first place.

In the second, we have a failure of feedback.  This boss cannot be harmed at all normally, and that's made clear enough.  Instead you have to operate some traps to injure him in particular fashion.  Unfortunately, it is possible to activate the traps in the entirely correct fashion, be off in timing by a small factor which is very difficult to estimate, and the whole process appears to fail.  Consequently I spent a while figuring out what to do, determined the correct answer, spent 5-10 mins executing it, determined that it didn't work, and moved on.  So the correct solution was now out of my potential problem space and led to frustration.  If there is going to be a crazy trick to hurting the boss, make sure that the player understands that they are going down a fruitful avenue.  It's fine to add a timing component; but have trick + failed timing provide relevant feedback.

All told I hit up GameFAQs three times through.  In the two cases above, and in another non-boss case where I ran into the failure of feedback problem (a puzzle; which is prone to that failure mode as well).  Thank goodness for GameFAQs... it at least lets sloppy design be an annoyance and not a showstopper.